it is a phrase becuase a phrase is a group of words that may contain either a subject or a verb but not both and the sentence "swimming laps at the pool" only contians a subject becuase, who is swimming laps at the pool?
Colin used to think he was going to be a humpback like his father, but when he started seeing Mary he started to have hope. Mary changed cause she found out how spoiled she used to be and wanted to help her cousin.
